Nowadays the conventional machine tools such as sander cutting-off machine, sawing machine or lathe are used to cut off or shorten the rods for the punch of punching die or the knockout bar of plastic die, and then the conventional grinding machine is used to grind the cut-off end surface of said rods up to the required precision length. However, it is difficult to cut off the said rods and grind the end surface thereof up to the required length with exact precision in the foregoing conventional manner, and even repeated measuring and grinding still cannot achieve the required precision length; and particularly, sometimes such phenomena will take place: the end surface of ground rods is not perpendicular to the axial center thereof, or even the rods are ground up to unduely short as an unserviceable salvage, so a new rod has to be cut off and ground. Therefore, this is rather wasting time, labour and material.
We inventors have been engaged in the plastic injection and extrusion molding as well as machinery and dies manufacturing and processing for many a year. In view of no special machine tool for precision cut-off and shortening of rods such as the punch of punching die or the knockout bar of plastic die and for grinding and flatening the end surface of said rods, and the conventional manner with the foregoing disadvantages, the present inventors mutually studied to manufacture and try the present invention which is a successful and practical "rods precision cutting-off and end surface grinding machine".